Testing and Improving Your Home’s Indoor Air Quality

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Worried about your respiratory health? Planning to order some popular products designed to make the air in your home more breathable? Do your research first. Not every air quality product has the quality that you need.

Dusty doorway in a home.
You don’t want to be the one living and breathing in this home. Image credit: dre2uomaha0.

Testing for pollutants might not produce as much useful information as kit manufacturer’s claim they do. Buying an air purifier might — or might not — actually improve the health of people with allergies or asthma. Plus, your vacuum cleaner might be making your air dirtier than it was before you used it.

Should You Test the Air?

You would think it’s just common sense to test the air quality in your home or office. After all, most people spend approximately ninety percent of their time indoors. The air is often more polluted and less healthy indoors than outdoors, according to the US Centers for Disease Control (CDC).

However, in many cases your nose and a flashlight are just as effective as an expensive testing kit. Elliot Horner, PhD, lead scientist for UL Environment, has two words — and more — for anyone thinking about buying a do-it-yourself test kit or hiring an inspector to take air samples. “Buyer beware,” he says.

Not all particles are the same

The main problem with testing kits is that they usually check for just one kind of pollutant. One kit might evaluate the air only for formaldehyde, while another looks only for mold, radon, mouse allergens or some other single toxic substance.

This means that, before ordering a particular test, you should already know what kind of pollution your house is likely to be experiencing. So, there’s little practical reason for conducting test in the first place. “Often, money is better spent addressing the problem rather than testing for it,” says Horner.

It’s also hard to tell if the kit that you purchased is even reliable. “I do not know of any way to evaluate one that would be available to the general public,” says Horner. While some might be certified by a product safety organization, UL no longer certifies air quality test kits.

Take mold, for instance. Testing for it in the air is a difficult process, which requires taking twenty or thirty samples. Result can be unreliable, according to Horner. “It’s more practical to search for mold with a good nose and strong flashlight,” he says.

Same goes for illnesses

Even if the results do properly identify which pollutants occupy your home, it’s “almost impossible” to know whether or not they are making you sick. Some people are very sensitive to small amounts of a pollutant, while others aren’t bothered by larger amounts. If you have more than one pollutant, it can be difficult to tell which one is causing your health problems.

One exception is Radon, a naturally-occurring radioactive gas that kills 21,000 people each year. You cannot see, smell or taste it, so testing is the only way to know if it’s present. So, the US Environmental Protection Agency (EPA) recommends that anyone buying or selling a home have it tested for radon.

Kansas State University sells an agency-approved testing kit. EPA also has resources online for locating a testing professional who will perform the test for you.

If you want a professional to test the air for you, find someone who is experienced with a variety of pollutants, according to Horner. This is especially important if you don’t know what kind of pollutants they should be looking for. Otherwise, they might blame your problems on whatever substances they are already familiar with.

“Stay away from the folks who do just one type of problem, such as mold or radon,” he says. “You want someone with an open mind.”

The Indoor Air Quality Association maintains a searchable database of professionals in your local area.

Also be wary of products that claim to provide easy solutions to your home’s air quality problems. Horner recalls the day he ran across a booth at a trade show, “selling some magic juice that will fix your mold without taking anything apart,” he says. “I threw the brochure away.”

Do You Need an Air Purifier?

The jury is out on the health benefits of installing air purifiers (often called “air cleaners”) to remove particles and gasses from your home.

Particulate matter is tricky

A series of medical studies have produced mixed results, according to Canada’s National Collaborating Center for Environmental Health. For instance, people with allergies, asthma or other respiratory illnesses who used portable air cleaners outfitted with HEPA filters had fewer symptoms, such as wheezing and coughing, but used just as much medication as people who didn’t use the cleaners. On the other hand, researchers found that ion generators (see below) produced no health benefits at all.

The US Environmental Protection Agency also has a mixed review of such products, but suggests that they can be used as one part of an overall plan, including removing “the sources of pollutants and to ventilate with clean outdoor air.”

Purifiers tend to work best at removing smaller particles like smoke, because they are relatively lightweight. Large particles, like pollen and dust, are less likely to remain floating in the air long enough to be collected. In some cases, a purifier can even make the air dirtier by stirring up already-settled dust.

“Studies have looked and often can not even show that particulate matter is reduced, much less a health benefit, in the real world rather than in a lab setting,” says Horner.

Horner points out that product testing is usually done in a laboratory. “The issue is that in the real world, there is often poor mixing of air. This means that much particulate matter (PM) in a room — in pockets of stagnant air — never gets pulled into the air cleaner. Also, even if the cleaner pulls in all PM that is in the air right now, if the sources of PM are not addressed, then PM levels very quickly will be right back up to where they were.”

Purifier designs fall into five main categories:

  • Mechanical. A fan forces air through a dense mesh, such as a HEPA filter, that traps the particles.
  • Electronic or Ion Generator. Electrical charges attract particles and either traps them in the machine or causes them to land on surfaces for later cleaning.
  • Hybrid is a combination of mechanical and electronic systems are used.
  • Gas Phase or “Sorption removes gasses, such as the smell of new paint, but not particles like dust or hair.
  • Ozone Generators produce ozone to supposedly “clean” the air.

Avoid ozone

Numerous authorities advise against using ozone generators, including the EPA and the Mayo Clinic. While all air cleaners produce some ozone as a byproduct, ozone generators deliberately fill the air with it in order to mask odors without actually cleaning the air itself.

Breathing ozone can cause lung damage that worsen existing respiratory illnesses, according to the US EPA. Some models can produce ten times more ozone than is considered safe. “People and ozone should not share space.” says Horner.

Electronic purifiers also tend to produce more ozone than mechanical models, although usually in smaller amounts, according to the California Environmental Protection Agency. Before purchasing one, ask for the manufacturer’s data on ozone levels.

Product ratings

Private industry rates air cleaners according to their ability to trap particles of various sizes. Two rating systems are most commonly used, MERV and CADR.

MERV, short for Minimum Efficiency Reporting Value, rates “whole house” purifiers that are typically installed as part of your building-wide heating and air conditioning system. There is a useful chart that you can consult, which shows how each MERV level performs against different types of particles.

For smaller, portable purifiers — typically used to clean a single room — look for the Clean Air Delivery Rate (CADR) label on the outside of the product’s packaging. Developed by the Association of Home Appliance Manufacturers, it rates the unit’s ability to remove tobacco smoke, pollen and dust.

Keep in mind that these rating systems have nothing to do with whether or not the unit will improve your health. All they do is measure the size and number of particles trapped. Even if an air cleaner does help, don’t make it your top priority. For instance, many allergens rest on surfaces, where you can vacuum or wipe them clean.

“There is no silver bullet,” says Horner. He advises people to reduce the sources of any pollutants, including keeping the home clean and appropriately ventilated. “Nothing all that fancy, what your grandmother was doing.”

So long as you avoid models that produce excessive amounts of ozone, there is no reason not to purchase an air cleaner if it makes you feel more comfortable. However, If you are considering purchasing one for health reasons, consult with your doctor first.

Is Your Vacuum Cleaner Bad for Your Health?

Running the vacuum cleaner regularly is one of the best ways keep a clean and healthy home. Unfortunately, not all of that dust stays in the machine. Some of it can escape through leaky spots or bad filters, spewing into the air and ending up in your lungs.

If vacuuming makes you feel uncomfortable, wear a dust mask. Then leave the house for a few hours, until the air clears. Even better, purchase a vacuum that keeps your air clean and maintain it properly.

Buy the right model for you

There are several types of filtration systems to choose from:

Central vacuum system. The vacuum is connected to a very long hose that either blows the debris out of your house through a vent in the wall or collects it in a disposal container stored in your garage. It is by far the cleanest method available, because nothing escapes back into the indoor air. However, the hose may prove cumbersome for some people.

Ultra Low Penetration Air filter. Called “ULPA” for short, this is the highest-quality filter that you can use with a household vacuum. It blocks particles as small as 0.12 micrometers with an efficiency rate of 99.999%.

High Efficiency Particulate Air filter. Called “HEPA” for short, this filter blocks particles as small as 0.3 micrometers with an efficiency rate of 99.97%. This is a good choice for household use, because it traps most of hazardous particles found in the home, such as bacteria, mold, pollen and fungus.

Hepa-Type Air Filter. While HEPA filters can be expensive, lower-cost alternatives are available. Sometimes called “micron” or “electrostatic” filters, they use various technologies to block particles as small as 0.3 micrometers. Some Hepa-Type machines work just as well as those with true HEPA filters, while others aren’t nearly as reliable. For the best quality, look for one with an efficiency rate of 98%.

At the low end of the scale is the common non-HEPA or non-HEPA Type vacuum, which only traps particles as small as 30 to 50 micrometers. This includes hair, dusts mites, and only the largest types of pollen and bacteria. If this is what you currently own, consider purchasing a better machine.

Other desirable features to look for include an exhaust filter, a well-sealed machine that won’t leak debris through the sides and (if you have a bag-type vacuum) micro-lined bags treated with an anti-bacterial agent.

Keep it in good working order

A clean vacuum is an efficient vacuum. Periodically clean the brush-roll of hair and fibers, then check the hoses and other air pathways for blockage.

If you have a HEPA filter, replace it with a new one every six to twelve months or if it gets noticeably dirty.

If your have a non-HEPA filter, you might be able to rinse it, dry and reinstall it several times before it needs replacing. Check with the manufacturer for instructions.

Empty or replace the container when it is no more than half-full of debris, in order to maintain airflow. Your most convenient option is to own a model with disposable bags, because you can throw them away with little fuss, so long as you handle them gently.

Bagless models cost less to maintain because you don’t have to keep buying new bags. However, emptying the canister requires preparation to avoid releasing debris into the air:

  1. Wear old clothes that cover all of your body.
  2. Put on a dust mask and grab and empty trash bag.
  3. Take the vacuum and trash bag outside.
  4. Carefully remove the canister from its housing.
  5. Place the trash bag completely over the canister.
  6. Slowly turn the canister upside down to empty it.
  7. After the dust settles, remove the canister from the bag.
  8. Tie the bag closed, allowing air to escape so it won’t explode.

Watch those mercury spills

Thermometers, thermostats and compact fluorescent (CFL) light bulbs contain a small amount of mercury, which is toxic to humans. If you break a bulb, the mercury can spill into your home environment.

Never use a vacuum or broom to clean up mercury. The force of the machine will either break it into smaller droplets or dissolve it into vapor, which can be inhaled. The CDC has an excellent set of instructions for cleaning household mercury spills.


David Arv Bragi, profile picture

David Arv Bragi is a multidisciplinary journalist with experience in health, safety, personal finance, technology, arts and cultural topics. He is also a former team leader and volunteer in community/tower emergency response teams. He currently lives just outside of Bellingham, Washington.